The biggest restoration project ever undertaken by the St Fagans: National History Museum on the outskirts of Cardiff has taken another step forward.

The first part of an intricate decorative rood screen has been placed in St Teilo's church, marking the beginning of its interior work.

The museum says it is a key day in the long-running project to rebuild the pre-Reformation church.

The first service is due to take place at the recreated St Teilo's next year.

The church, which originally stood at Llandeilo, near Pontardulais in west Wales, is being faithfully rebuilt to recreate its appearance in the year 1520.

The painstaking restoration has involved rebuilding church stone-by-stone, like the rest of the museum's exhibits from around Wales.

Carpenter Ray Smith has devoted years to the project

The first part of the wooden screen, intricately carved from Welsh oak and recreating the legend of the Welsh saint, has been positioned inside the church.

The loft balcony and the rest of the screen has been carved by carpenter Ray Smith, who has relinquished his management job at the museum to concentrate on the project.

Most rood screens were destroyed during the Reformation, and the museum said St Teilo's was the only one to be carved anew in living memory.

Mr Smith has spent years travelling throughout the UK to try to find similarities and patterns, but he was determined not to copy another rood screen.

He said: "In my experience no two screens are the same, but one fine example in a Cirencester church and another from a church in Old Radnor both almost certainly came from the same workshop.

Tools for the work have been found in car boot sales

"You can still buy a few chisels of the same patterns as they would have been used in medieval workshops, but most of my tools are gathered from years of foraging at car boots sales and specialist fairs."

The remainder of the rood screen will be erected during the year.

It depicts the legend of how St Teilo, the patron saint of fruit trees and horses, fled to Brittany to escape yellow fever in 545 AD.

"The screen will be painted in greens, blues, reds and gold leaf and panels depicting the 12 apostles will be placed along the front of the rood loft's balustrade," said Mr Smith.

The museum has not revealed the cost of the St Teilo's project, but education interpret Elin Phillips said it was the biggest ever undertaken at St Fagans.

The church as it was four years ago

The public have been allowed to watch the traditional building methods and techniques employed.

"We are trying to be open and transparent about what is going on behind the scenes and have allowed visitors to see the building work in action," she said.

"People come back regularly to see what is going on."

"This is the first stage of recreating the look and feel of the medieval church. It's very exciting," she said.

As well as the rood, the restoration will now involve artists working on site on copies of 16th Century wall paintings uncovered in the church.

St Teilo's will be officially opened as part of celebrations of the National Museum & Galleries of Wales' centenary in September 2007.